九年级英语定语从句：   

        引导定语从句的关系代词有：that（指人或物）, which（指物）, who（指人）。指人时可用that或who，指物时可用that或which，但有时只能用that不能用which。常见的情况有下列五种：
1. 当先行词是all, any, anything, everything, nothing或被它们修饰时。例如：
        Is there anything that I can do for you?
        有什么可以为你做的吗?
        All that can be done must be done.
        凡是能做的都必须做。

 2. 当先行词被形容词的最高级或序数词修饰时。例如：
        That is one of the most interesting books that are sold in the bookshop.
        那是这家书店出售的最有趣的书之一 。